Many of these local "contests" are nothing more than a fundraiser for a local organization and not really much of a contest at all. I personally steer clear of any that ask me to cook and feed the public samples, especially if I'm expected to supply the meat.
If you have a local vending/caterer/restaurant business then it may pay off in terms of drawing in new business. I think for a new team wanting to try and start competing they're not really a good idea. I think you are better off starting out at a sanctioned event.
"What sort of people are these charcoal masters? They behaved badly and were unconcerned with appearances. Their hair was long and unkempt and their clothes were wrinkled and old. They drank beer to and from the crab house and they made rude noises while we cooked." Tao of Charcoal